Recently replaced one of the front suspension springs on my SLK 280 (2006) which was broken. I have a tip which may help others wishing to do this. The rebound damping is quite strong on these cars, so when spring pressure is released when the top nut is removed from the clamped spring, the rod goes back into the damper body to such an extent that the new spring cannot be compressed enough to get the top nut on. You can get round this by holding the damper extended using a strong good quality hose clip tightened around the rod up against the damper body prior to compressing the spring OR if the spring is broken and rod has dropped, put the nut back onto the top of the rod once the spring etc is removed, hold the nut in a fairly substantial vice, get your strong pal to pull and hold the damper body out whilst you fasten your hose clip in position. Don't forget to remove the clip before you fit the leg to the car.